Question: The sum of $3$ consecutive odd numbers is $69$. What is the first number in this sequence?
Solution: Call the first number in the sequence $x$ The next odd number in the sequence is $x + 2$ The sum of the $3$ consecutive odd numbers is: $x+ (x + 2)+ (x + 4) = 69$ $3x + 6= 69$ $3x = 63$ $x = 21$ Thus, the first number is $21$.